Scale mechanism for electrical measuring instruments.



R'. P. BROWN, C. P. FREY AND F. WAGNER.

.SCALE MECHANISM FOR ELECTRICAL MEASURING INSTRUMENTS. APPLICATION FILED MAR. 4, IQIB.

1,320,120. I Patented 0@I.2S,I9I9.

Z SHEETS-SHEET 4a ATTORNEY.

R.-P. BROWN, 0. P. FREY AND F. WAGNER. SCALE MEC HANISM FOR ELECTRICAL MEASURING INSTRUMENTS.

' APPLICATION FILED MAR.4.19I9. I 1,320,120. Patented Oct. 28,1919.

2 SHEETS-SHEET Z.

tftFh ItQEQ BICI-Ir P. 1539?? N, CHARLES E. FREY, AND FRIEDRICH VTAGNER, OF PHILADELPHIA, PEIINSYLVANIA, ASSIGNORS TO THE BROWN INSTRUMENT COMPANY, OF PHILA- PENNSYLVANIA, A CGRPORAIION OF PENNSYLVANIA.

SCALE MECHANISM FOR ELECTRICAL IVLEASURING' INSTRUMENTS.

Specification. of Letters Patent.

T l-atcntcd let 2%,

90' of what is ca i 55 net-tion w Application filed March 2',

had to the aceonn ianying drawings, which tot-hi a part thereof.

Our invention relates to scale mechanism for electrical ineasuz'ing instruments lDVOlV- inn a the at consistii'ig of a resistance wire and a n .7 hle element fol determining the potential hetw two points on said Wire. Frinnnzly our i: ition is designed for use in connection "uh/l1 theLrheostat in the form lied the slide wire in instruments twown as "onietei's.

The object invention is to in'ovide and make 1.):- e the use a long); scale oecnnyf d compact space in con A i, instrument and broadly speaking our iignei'it-ion eonus s in provid ing the instrumen With o} lindrical rotating Sl.lP; )Oi"tlDf in for the slide wire on which the slidewice, coiled around the cyl .o of; a spil -ah is seen 2th in providing further a rotating scale support ing cylinder, rotating synch onoi'isiy with and act/na Of. cit ts toi iing an exitem sion of, or: a part of m nimizing cylinder, on which is ed a spiral scale rrespondiv: in pitch the spiral dings of the YQUUE'JTKHCQ Wire and index: 1'"

n no ii'e fey-dc V i-the ordinary ien'ients of potei'itiomctc-r the potentiai net Ween pointson the resistance Wire.

'WVL

line nature i our iiwention Will be best undei'stood as scribed in connection. with the drawings in whichl igure 1 is a diagramm tic showinqof po entiometer as a Whole showi elevation our new 'fi'i-tt; at

a true and exact description,

191%? Serial No. 280,530.

carrying cylinders and the slide carrying the HKlCl-I and wire contacting slide.

Fig. 2 is a side elevation taken in section through the face plate of a casing contain-' ing the instrument and the index siide,and

showing a simple device for rotating the cylinder.

Fi on the line to Fig, 9, show it Wi.

usual small dry continuously wire from A. to

indicated at i ieostats at (I and a standard cell, the side connected i'jhi'oug'h the standard with a vanoznetef F, and the of the slide Wire, G and G are pos" to Whicl'i the source of 't'al, to he tested are connected in circuit tli'ough the key S and the sliding element 5 which and by moving: which the E. M. F. source of vntial is determined.

in all the indicated and described features except as to the scale and index mechanism shown in connection with the diag'larm the diagram illustrates an old and familiar con- St-YHClJlOEl.

P Oll'lll P "is the winch 1e slide The oi'r.lina1 3/' resistors and D", and the ordinary (v \1 E indicat vhich is coil trey SC let x i ot the cy l i n d or; the cylinder H is a guideway shown as a groove H, and as shown, a conical friction surface H is forn'ied at one end of the cyltop.- The cylinder i is secured to a rotatable shaft I journaled 1 the. top and bottom in anus J, J, seci'nred the face plate K of the instrument This ce plate is foamed with a sight opening a hearing K for the shaft 0;; and it iding contacting element F movable over the slide Wire 

